Disk recording and/or reproducing apparatus have hitherto been provided to record and/or reproduce information signals from disk-like recording mediums generally called an optical disk such as a CD (compact disc) or a CD-ROM (CD-read-only memory), a magneto-optical disk (OD: optical magnetic disk) or the like.
This disk recording and/or reproducing apparatus comprises: a disk rotation mechanism for rotating a turntable onto which a disk-like recording medium loaded, an optical pickup device for writing and reading an information signal on the disk-like recording medium rotated by the disk rotation mechanism, and a disk loading mechanism for transporting the disk-like recording medium between a disk entrance and exit slot through which the disk is inserted and ejected and a disk loading portion having a turntable and the like.
As the disk recording and/or reproducing apparatus including such disk loading mechanism, there is known such a disk recording and/or reproducing apparatus as described in Japanese laid-open patent application No. 10-340513 for example, and a schematic arrangement of such disk recording and/or reproducing apparatus is shown in FIGS. 51 and 52 of the present application.
In FIG. 51, reference numeral 1 denotes a disk recording and reproducing apparatus. The disk recording and reproducing apparatus 1 includes: a drive unit 2 provided within a housing for clamping to drive a disk D (e.g. a large-diameter disk D12 having a diameter of 12 cm or a small-diameter disk D8 having a diameter of 8 cm), a disk guide 3 extended at one side portion within the housing along the direction of the disk D being transported, a stopper 4 provided at the deep inside of the housing and extended in the direction crossing the disk guide 3 and a disk conveying means 5 for conveying the disk D to the deep inside of the housing and forcing the disk to be transported in the direction of the disk guide 3 when the disk is conveyed. This recording and reproducing apparatus is characterized in that the center of the disk D is clamped to the drive unit 2 when the disk D conveyed by the disk conveying means 5 is abutted on both of the disk guide 3 and the stopper 4 to be properly positioned.
The disk conveying means 5 includes a tapered roller 6 which is thicker on the side of the disk guide 3 and a guide top 7 for holding the disk D between the guide top 7 and the roller 6. The roller 6 is shaped like a tapered roller whose diameter progressively increases from the Y2 side to the Y1 side. The roller has a spiral protrusion 6a formed on its outer peripheral surface. Both ends of the roller 6 are rotatably supported by a roller support body 8, and the roller can be rotated in the a direction and in the opposite a direction shown in FIG. 51 by a drive motor not shown in the figure. The guide top 7 is provided above the roller 6 and the roller 6 is forced to the side of the guide top 7 under spring force of springs 9, 9 retained at the both ends of the roller support body 8.
In the disk recording and reproducing apparatus 1 having the above-mentioned construction, when the disk D is inserted into the space between the roller 6 and the guide top 7, the disk D is held between the roller 6 and the guide top 7. When the roller 6 is rotated in the a direction in this state, the disk D is conveyed in the X1 direction by rotation force of the roller 6.
In this case, when the large-diameter disk D12 is inserted into the disk conveying means 5, since the diameter of the Y1 side of the roller 6 is larger than the diameter of the Y2 side, the edge portion on the Y1 side of the large-diameter disk D12 is held by large force, and the edge portion on the Y2 side of the disk D is held by small force or not held at all. As a result, difference is generated between holding forces at both left and right ends of the large-diameter disk D12 so that feeding force generated by the rotation of the roller 6 strongly acts on the large-diameter side as compared with the small-diameter side. Consequently, the large-diameter disk D12 is transported in the X1 direction which is to the deep inside of the housing while being forced against the disk guide 3, that is, in the Y1 direction. Then, when the large-diameter disk is brought in contact with the stopper 4, the large-diameter disk D12 is properly positioned by the disk guide 3 and the stopper 4.
When the small-diameter disk D8 is inserted into the disk conveying means 5, the roller 6 is also rotated in the a direction, whereby the small-diameter disk D12 is transported in the X1 direction which is to the deep inside of the housing while being forced in the Y1 direction. Similarly to the large-diameter disk D12, the small-diameter disk D8 is also conveyed to the position at which the disk is brought in contact with the stopper 4 while being forced against the disk guide 3. Then, when the small-diameter disk D8 is brought in contact with the stopper 4, the disk is properly positioned by the disk guide 3 and the stopper 4. Reference numeral 08 denotes the center at which the small-diameter disk D8 is properly positioned, and reference numeral 012 denotes the center at which the large-diameter disk D12 is properly positioned.
However, in such conventional disk recording and reproducing apparatus, the roller 6 and the guide top 7 comprising the disk conveying means 5 hold the front and rear surfaces of the disk D and the disk D is conveyed in the X1 direction by the rotation force of the roller 6 while the disk being forced against the disk guide 3, that is, in the Y1 direction. Consequently, when the disk D is inserted into the space between the roller 6 and guide top 7 in the state, for example, in which the signal recording surface is smudged by minute foreign substances (dusts, etc.), foreign substances are pressed against and dragged on the signal recording surface by the roller 6 so that the signal recording surface may be covered with the foreign substances or scratched. In consequence, when the signal recording surface is covered with the foreign substances or scratched, not only the signal recording surface looks considerably damaged but also a signal recorded beforehand cannot be read out from the optical disk and a new information signal cannot be written on the optical disk.
In view of the above described problems in the prior art, according to the present invention when the disk-like recording medium is inserted into and ejected from the disk recording and/or reproducing apparatus, a disk transport mechanism side can be prevented from coming in contact with a signal recording surface of a disk-like recording medium so that the signal recording surface can be protected from being scratched and the disk transport mechanism side can transport disk-like recording mediums of different sizes by holding only their outer peripheral edges.